Firefighters quickly extinguished a small structure fire that broke out Tuesday morning at the site of the new $71 million housing development on DeWert Avenue.

The fire remains under investigation, but does not appear to be suspicious, Deputy Fire Chief Scott Dexter said. A handful of construction workers had been working in the unit at the time of the fire.

“There’s some minor damage to the third floor,” he said. “Nobody got hurt.”

Construction crews, funded in large part by a federal HOPE VI grant, are building new mixed-income housing units at the site to replace the demolished DeWert Avenue housing project. The $71 million project will have 88 energy efficient townhouse-style units on the site of the former Fairfax Gardens public housing complex on DeWert Avenue, and 72 affordable rental units on the former Parcel 6A brownfield site off Mason Street.

Taunton Housing Authority Director Colleen Doherty said the fire was “under control” by the time she arrived on scene shortly after 11 a.m.

The fire started on the top level of a three-story building under construction.

“It doesn’t look too big,” Doherty said.

Some of the damage, Doherty added, appears to be from water. The sprinkler system in the building activated during the fire.

Under the public-private partnership that was forged to launch the construction project, Trinity Financial will own and operate the new building, while the Taunton Housing Authority will maintain ownership of the land.

Funding is being provided by the Taunton Housing Authority, the city, HUD, the Massachusetts Department of Housing and Community Development, MassDevelopment, RBC Capital Markets, Bank of America and Merrill Lynch.

The new HOPE VI project remains on target to fully open by the end of January, Doherty said. Some sections will be completed sooner, and the first residents may move into the new homes as soon as Oct. 1.